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J. B. DRISCOLE.

Hot-Air Furnance.

Patented Oct. 6. I868.

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J. B. DRISGOLE, OF NEW YORK,- N. Y.

Letters Patent No. 82,811, dated October 6, 1868.

IMPROVEMENT IN nor-AIR FURNACES roe HEATERS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, J. B. DRISCOLE, of 234 Water street, city and county of New York, State of New York, have invented a new and useful Improvement in Furnaces for Heaters and other purposes; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part ofthis specification, in which Figure 1 is a vertical cross-section of a furnace which illustrates my invention, thesection being made in i the plane of the line at x, fig. 2, and the view being taken from right to left.

Figure 2 is a plan.

, This invention relates to furnaces for heaters and other purposes, and consists in providinga lateral extension of the fire-box, in which is placed a supply of fresh fuel, ready to be delivered into the fire, 'as the same shall be required.

In this example, I have shown the extension applied to the furnace of a heater, of that class, which, when set up, is usually surrounded by a case of brick ormetal, but the invention is applicable to all kinds of furnaces, and is valuable where bituminous coal is used for fuel.

The letter A designates the fire-pot, and B the supporting-base of a heater. 0 is the ash-pot opening,

and E the ordinary opening in the front of the furnace, through which the operations of kindling, and inspecting, and stirring the fire are conducted. The letters F F designate pipes, that enter the sides of combustionchamher' D, through which pipes a constant and unobstructed supply of air to support combustion is admitted into the furnace above or at the surface of the fuel.

I make the fire-pot A' with an extension, Gr, which, in this example, is placed at the left-hand side of the furnace, observing fig. 1, but it may be placed on either side of the front or at the rear, according as convenience suggests. The fire-pot and its extension are cast or made in one piece, and the height of the extension, at K, where itjoins the circular wall of the fire-pot, is about equal to the whole height of the fire-pot, extending downwards nearly to the level of the grate, and upwards nearly to the upper rim of the fire-pot. The said extension is: carried in a general horizontal direction outwards far enough to bring its mouth, H, outside of the usual case, which surrounds furnaces of the description to which my invention is applied, and it is contractedin dimensions in a uniform manner, as it-proceeds outward up to its mouth II, which is provided with a circumjacent rim, L, with a turned-up edge, in which rimI place a. casing, M, of soapstone, for the purpose of avoiding'the bad efi'ects of rust, which is productive of much inconvenience and damage, when a metal door closes against a'casing of the same material.

A door is placed at the mouth H, in the ordinary manner, so as to close it tight, and prevent the entrance of air from without, wherebyany fuel placed in the extension, being excluded from the atmosphere and from currents of air or gases through it, is kept from burning, and is decomposed, if at all, only by the action of the heat radiated or communicated from the fire-pot.

When my invention is applied to a furnace or fire-potwhich is not enclosed by a casing in the usual manner, suitable provision must be madefor properly supporting it in its horizontal position, so as to obviate any danger of its being broken down by its own weight, and the weight of the coal with which it may be charged.

The mode of operation of my invention is as follows:

The fire is got under way in the fire-pot in the usual manner, the fuel, wood and coal, for that purpose being introduced through the doorway E, at the front, or through the extension G, as may be preferred. The additional fuel required to keep. the fire up is supplied by means of the extension G, which is filled with coal, through-its doorway, H, and said doorway is then closed tightly.

. The coal or fuel that lies on the grate of the fire-pot will burn actively, by reason of the supply of air which reaches it through the grate, but the fuel in the extension G, being deprived of airto support combustion, will not become ignited, excepting that portion which is near the place where the fire-pot and extension join each other, but such fuel being nevertheless exposed to a great heat from the burning fuel in the fire-pot, will part, to a large degree, with its constituent gases, as in the case of coal exposed to heat in an ordinary retort, and such gases will pour out therefrom and enter the fire-pot, in which, and in the gas-combustion chamber above, they will unite with the air'whichentcrs through the air-pipes F, and through the grate,

and become consumed.

As the fuel on the grate wastes axvay, a proper quantity is shoved out from the extension G, and fresh coal putin said extension to take its place. As thecoal in the said extension becomes heated, it will expand more and more, and therefore I form said extension in such a manner that its capacity increases as it nears thefire-pot, and thus gives more room for the expanded fuel.

I do not broadly claim forming an extension on the side of the fire-pot, as described in the patent to E. Sawyer, of 1865, and in'the patent to L. G. Fisher, bearing date May 8, 1849; but having thus described my invention,

What I claim as'new, and desire to secure by Letters Patent, is-- V The fire-pot A, with a'horizontal extension, G, of"pyramidal or conical form, constructed and operated substantially as and for the purpose set forth.

In testimony whereof, I have hereunto set my hand, in presence of two witncsse J. B. DRISCOLE.

Witnesses;

J. VAN Ssnzrvoonn, JOHN 0. Pentax. 

